The main reason Netflix is more convenient than piracy is that piracy is illegal. If The Pirate Bay was allowed to offer a $2/month unlimited movie streaming service with no legal repercussions, Netflix would be out of business.
Hey don't discount the work that various actors did to make piracy less convenient as well. VPNs and upload caps, not to mention putting all the infrastructure and ops in place to force people to use them made piracy harder than it technically needs to be.